Window or windscreen wiper mechanisms



l 1968 E. D. WYNN ETAL ,3

WINDOW OF WINDSCREEN WIPER MECHANISMS Filed June 13, 1966 Edward Donald.Cheltenham, an d Charlies Geoffrey .Longford, Quedgeley, nearGloucester, England, as-

"signers to Wynn Development Limited, Ch'eltenl anj,

England Filed June13, 1966, Ser. No. 557,143

Claims priority, applicationGreat Britain, Aug." 6, 1965,

7 Claims. (Cl. 15250.24) r i ABSTRACT-:OETHE DISCLOSURE-f Awiperassembly which acarriage for a wiper blade is i'e'cip'rocated bymeans'of a link "Inemberhidgedto said carriage and to a bracketr'nemb'er connected' 'to an endless belt passinga'round two sprockets;The connection between'the bracket member and belt is achieved byproviding projecting means extending'outvvard from the bracket memberand gripping the belt;

' The present invention is an improvement in orm odification of thatforming the subject of our" prior U S'. Patent'No. 3,042,954 which fisconcerned'with window or windscreen wiper mechanism 'in'cluding'acarriage slidable to and fro between, guides and carrying a wiper bladesupporting arm, an endless belt passing around spaced pulleys,'one d'fvvhich is drivenby means ofian electric motor or other driving mechanismt'o impart a unidirectional movement to 'said belt and means connect:ing said belt to the carriage to impart a straight line motionto thewiperbla'de'or blades. p The earlier construction included aclip or padof arduate-shape which was attached t'd'the belt, the radius of the arcapproximating to the radii of thepulleys around which the belt and itsassociated, clipfor pad had to pass.

Such a construction was particularly, suitable for use with a belt ofV'shape in cross-section but'was "applicable to belts of other shape,perhapszto' a 'le'sser'extent. i

The present invention is concerned with the connection of the carriageto the belt, the device in accordance with the present invention havingbeen specially designed for use with belts of the flat or power griptype, the latter comprising a generally flat belt formed with integralspaced inwardly directed transverse projections or ribs for enteringspaced notches in the pulleys to prevent belt slip.

In the construction disclosed by the specification and drawings of theprior patent, the belt was connected to the carriage by means of aconnecting rod or link, but it is within the scope of the invention toemploy any suitable means such as for example a form of scotch yokeengaged by a laterally projecting pin or its equivalent mounted on thebelt.

The chief object of the invention is to evolve a method of connectionbetween a belt and some other component which will not impair thenatural flexibility of the belt or interfere with the passage of thebelt and its associated connection around the pulleys or rollers eventhough they may be of small diameter.

The invention consists broadly in forming the belt with a tuck at theconnecting point, the tuck being directed outwardly of the belt andenclosing a pin or other driving member.

It will be appreciated that when the invention is applied to a beltformed with equally spaced projections or ribs for entering notches inthe pulleys, the provision of a tuck in the belt must not under anycircumstances vary the longitudinal spacing of the projections in thevicinity of the tuck and consequently it is proposed ac- Patented sar -v9 cording to a further feature of the invention to soform the tuck that.the spacing of the projections immediately below the tuck are equal tothe spacing of the notches in'the pulleys or are exactly equal to twicethe spacing of the notches in the pulleys to ensure that when thatpartofthe belt ,passes over a pulley the projections .will enter thenotches without difliculty. e

Referringto the accompanying drawings: I I

FIGURE 1 is a longitudinal section on the line A-B FIGURE 2 of oneformof driving pad in accordance with the invention and its associatedbelt; J 1 7 FIGURE 2 is a transverse section on the line C-D in FIGURE1; I g FIGURE 3 is a section on the line E-Fin FIGURE 4 illustrating amodified construction; y, I I

FIGURE 4 is a section on the line G;H in FIGURE ,3; FIGURE 5 is a .planview of the driving pad illustrated in FIGURES 3 and 4; and v v FIGURE 6is a sectional side elevation of a modified construction.

As disclosed in applicants above-identified US. patent, a straight linereciprocal wiper motion is achieved by means of an endless belt passingover two spaced pulleys, and driven by means of an electric motor or thelike connected with one of the pulleys. A carriage for the Wiper bladeis provided which is permanently connected with the endless belt bymeans of a link hinged at one end to the belt and at the other end tothe carriage. Therefore, upon driving one of the pulleys, the end of thelink hinged to the belt travels in an endless path and impartsreciprocal movement to the carriage and therefore to the wiper blade.

The present invention is concerned with the particular connectionbetween one end of the link 11 with the belt 1, while permitting thelatter to pass over the pulleys. As shown in FIGS. 1 and 2, the belt 1has a series of transversely arranged longitudinally spaced projectionsor ribs 2 which are intended to enter a series of correspondingly spacednotches 3 in two spaced pulleys 4 one of the two pulleys being shown inFIGURES 3 and 4.

'As will be seen clearly in FIGURE 1 the belt 1 is formed with a tuckgenerally indicated by 5, the belt being bent about a transverse axis sothat the two projections 2 adjacent the bend abut, the next two adjacentprojections being spaced apart an amount 2a exactly double the normalspacing a. In this case when the tuck passes over a pulley one of thenotches in the pulley lying beneath the belt will not be entered by aprojection but this will not materially adversely afiect the drivebetween the pulley and belt.

The driving pad indicated generally by 6 takes the form of a bracketcarrying three laterally projecting spaced pins 7 which are threaded attheir extremities to receive securing nuts 8 which engage a loose link 9drilled to receive the three pins.

The pins are so spaced that the belt is held firmly in the shape of atuck, the belt being in addition gripped between the bracket and theloose link when the nuts are tightened.

The bracket 6 includes an olfset part 10 having an axial protuberanceforming a bearing for a link 11 intended to move a carriage carrying awindscreen wiper arm, the link being located between part 10 and a disclike member 12, parts 10 and 12 being threaded or otherwise connectedtogether.

The pins 7 may carry distance sleeves 13 or may be of increased diameterintermediate their ends to form shoulders against which the link willabut to limit pressure on the edges of the belt.

In the case of the modified arrangement shown in FIGURES 3 to 5, thedriving pad 6 is of substantially rectangular shape in plan and ofsubstantially arcuate a rectangular slot "or opening through which thetuck' in the belt is passed, a pin 14 having a length greater than thelength of the slot being passed through the tuck and maintained in thatposition by two split pins 15 passing through diametral holes in the pinnear its extremities. In this case the distance a separating theprojections 2 on the belt immediately below the pad is the same as thedistance a separating the remainder of the projections,.the arcuateformation of the pad enabling the latter to pass easily around thepulleys. The remainder of the pad corresponds substantially with the padshown in FIGURES 1 and 2.

The pad 6 shown in FIGURE 6 has been designed primarily for use withfiat belts devoid of projections or ribs. The construction is verysimilar to that shown in FIGURES 1 and 2 except for the fact that thethree pins 7 are arranged in the form of a triangle to fit closelyaround the belt. The pins may be screw threaded at their extremities toreceive securing nuts engaging a separate link or plate whereby the beltwill be gripped at its edges to connect it firmly to the pad, the beltpassing freely over the pulley without interference.

The two outer pins support the belt against outward radial displacementand the central pin against inward radial displacement, the central pinbeing enclosed by the tuck.

It will be appreciated that in the case of the power grip type of belt,accurate registration of the projections or ribs with the notches in thepulleys will be maintained and due to the fact that in all cases theparts of the belt on the inside of the pad are free to move inwardly toconform to the periphery of each pulley, the belt will pass aroundpulleys of quite smaller diameter.

' We claim:

1. A wiper assembly comprising a pair of spaced sprockets, an endlessribbed belt passing around said sprockets, a bracket member havingprojecting means extending therefrom, a portion of said belt beinggripped by said projecting means to fasten said belt to said bracketmember, said belt being folded outwardly so that said portion thereofconforms to the curvature of said pulleys, a carriage for wiper blades,a link member hinged at one end to said carriage and at the other end tosaid bracket,

andmsans Q E Y'? an? 9 q u e t impart pr qa movement to said carriage.

2. The assembly of claim 1, wherein said projecting means is in the formof three laterally spaced pins, said pins being so positionedfthat onepin is enclosed by the foldjrin'the belt, the 'belt'being'of the flattype, the portions of the belt on opposite 'sides of the fold lyingbeneath'theremaining pins'and beingfree to move radially inwardly toadapt themselves-to the curvature of the pulleys.

3. The assembly of claim. .1, wherein said projecting means gis intheform of three laterally projecting pins all lying in substantially thesame plane, the fold in the belt enclosing the central pin, the portionsof the belt on opposite sides of the fold passing between the centralpin and the outer pins lying beneath the outer pins, the pins bein'g'soarranged and constituted thatthe ribs on the'belt lying .beneath saidbracket are spaced apart an amount equal to double the normal spacing ofthe ribs to insure correct meshing of the ribs with said sprockets.

4. The assembly of claimt3, wherein the ribs on the belt lying withinthe 'fold abut face to face.

5. The assembly of claim 1, wherein said bracket is formed with arectangular shaped slot through which the fold in the belt projectsradially outward and wherein said projecting means is in the form of apin having a length greater than thewidth 0f the belt and the width ofthe slot, the ends of the pin projecting beyond the longitudinal edgesof the slot abutting the upper surface of the bracket adjacentthe edgesof the slot, the ribs on the belt lying within the fold abutting face toface. 1

6. The assembly of claim 5, wherein .the fold is so constitutedthat thenormal spacing of the ribs on the belt isunaffected, the portions of thebelt lying beneath the" bracket being free to moveradially inwardly toconform to the curvature of said pulleys.

7. The assembly of claim 5, wherein said pin is bored radially at itsextremities, and further comprising a pair of split cotter pinsextending through the bores to hold the pin in position.

No references cited. CHARLES A. WILLMUTH, 'P rimary Examiner.

ROBERT I. SMITH, Assistant Examiner.

